This invention relates to a display device with a memory which is connected to a large number of terminal units to for storing an indication of the actuating signals produced from the terminal units upon the actuation of the units in the order of their actuation and then for displaying the reference number of the terminal units thus actuated in the order of their actuation.
In the case, for example, of a fire warning system incorporating a great many fire sensors as the terminal units, since the conventional system employs display units for indicating the actuation of every terminal unit in a central display device, the central display device must be large in size and have a primitive display function. In addition, the conventional random display function of the display device is disordered compared with the display device improved according to this invention which can display the information in the order of reception of the information from a large number of terminal units and which can also repeatedly display the information in the received order to dynamically display the actuating conditions of the information supplied from the terminal units.
In case environmental changes in a certain restricted planar region or three-dimensional space are detected by the terminal units collectively provided therein, it is not necessary to provide the same number of display units as terminal units to display the actuation of the terminal units. This is because the status of the environmental changes which take place thereafter are desirably observed in relation to the place where the changes first occurred and can be accurately appreciated by observing the direction of movement of the changes in comparison with the spatial placement of the actuated terminal units. The amount of the information becomes extremely small when the information is grasped linearly with respect to the lapse of time as compared with the case in which the information is grasped spatially.